Question

The pitch of a screw gauge is 1 mm and there are 100 divisions on the circular scale. In measuring the diameter of a sphere there are six divisions on the linear scale and forty divisions on circular scale coincide with the reference line. Find the diameter of the sphere.

Answer 1

Diameter of the sphere is:

Least count of screw gauge = $\frac{Pitch}{No. of circular Divisons} = \frac{1}{100} = 0.01 mm$

Diameter of sphere = Linear Scale Reading + (Circular Scale Reading * Least Count)

Linear Scale Reading = 6 * 1 mm = 6 mm

Circular Scale Reading = 40

Diameter = 6 mm + (40 * 0.01 mm) = 6.4 mm

Answer 2

The diameter of the sphere is 6.4mm

• Let us go through the given parameters

        Pitch(p) = 1mm

       Main scale divisions = 40

       Linear scale divisions = 6

• Least count of the screw gauge is L.C= (pitch / number of circular divisions)

                                                              =1/100=0.01mm

• Linear scale reading (LSR) =6×1mm=6mm

• Circular scale reading (CSR) =40

• Diameter of the sphere =LSR+(CSR×L.C)

                                       =6+(40×0.01)=6.4mm

• Therefore,Diameter of sphere is 6.4mm